v von dee poppenburg



(No Model.)

J. VON DER POPPENBURG.

GALVANIG' DRY BATTERY.

No. 504,746. Patented Sept'. 12, 1893.

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u; y y f CNTTED STATES PATENT OFFICE.

JOHN VON DER POPPENBIIRG, OF CHARLOTTENBURG, ASSIGNOR TO CARL CHRISTIANLESENBERG, OF ROSTOCK, GERMANY.

GALVAN lC DRY BATTERY.

SPECIFICATION forming part of Letters 'Patent No. 504,746, datedSeptember 12, 1893.

Application led October Il, 1892. Serial No. 448,599. (No model.)

To @ZZ whom it may concern:

Be it known that I, JOHN von DER Port-EN- BURG, a subject of the King ofPrussia, German Emperor, and a resident of Charlottenburg, near Berlin,in the Kingdom of Prussia, German Empire, have invented certain new anduseful Improvements in Galvanic Dry Batteries, of which the following isau exact specifica-tion.

1o My invention relates to improvements in galvanic dry batteries, andconsists first in employing a novel filling material of great cheapness,as hereinafter' described whereby the constancy of the current yieldingis prer5 served for a long time.

My invention secondly consists in soaking the carbon electrode in asolution of hydroxide of chrome, prepared in a particular manner, to bedescribed hereinafter.

2o My invention will be more readily understood by reference totheaccompanying drawings, in which- Figure l is a central elevation of myimproved dry battery. Fig. 2 is a similar view of a modication. Figs. 3and 4 are plan views corresponding to Figs. l and 2 respectively.

Similarletters denote similar parts throughout the several views.

VIn Fig. 1 c is a zinc vessel or cup forming the cathode of the cell andcontaining the v exciting substance n, the composition and preparationwhereof will be described hereinafter. In the center of the said zinccup a I place the cylindrical hollow carbon electrode b, which is madetapering at its upper end, as shown. The opening at the bottom of thecarbon cylinder h is closed up bya cork 7c, but previously I insert asmall quantity of 4o hydroxide of chrome, as shown at m, prepared in amanner presently to be described. The carbon electrode is impregnatedwith a solution of said hydroxide of chrome. TWhen all parts areinserted in their right position, the

cell is closed at the top by means of a cork or similar substance madeimpervious byacoating of pitch, as shown at p.

In Figs. 2 and 4 I have shown a modication in which the positions of themetal and 5o carbon electrodes have been reversed. In all other respectsthe construction of the cell is the same as before described, and willbe readily understood by the aid of the letters of refencemarlred on thedrawings.

In carrying my invention into eect, I fill the cells with Iinely choppedor ground fibrous materials, such as straw, chaff, and other vegetablematters; these substances, and this is a feature of my invention, arescalded in hot water, and may then be used for filling the cells. Iprefer to mix the chopped straw or other vegetable matter with hydratesof carbon, such as dextrine, glucose or starch. This is anothercharacteristic feature of my invention, and in this case I add such aquantity of water that the entire mass is moist in itself, yet will notexode any water or moisture. The addition of hydrates of carbon ishowever not absolutely necessary.

A further characteristic of my invention consists in im pregnatin g andpartly lling the carbon cylinder with a hydroxide of chrome prepared ina particular manner. This hydroxide of chrome is prepared in thefollowing manner: I take common bichromate of potash, dissolve it in hotwater in such a degree, that the solution is perfectly saturated. Then Ipour this solution in sulphuric acid, and precipitate thereby hydroxideof chrome, which is again dissolved in water. The carbon cylinder issteeped in this solution, so that it is soaked thoroughly with hydroxideof chrome, and I also fill a small quantity of the precipitate into thehollow of the carbon cylinder, which is finally closed by means of acork, as described.

The filling material constituted by the scalded chopped straw or othervegetable matter is humid enough to effect the produc tion of acurrent., but will not give off any moisture.

My improved dry battery yields a very constant current and remainsactive for a very long time, especially,if it is given a period ofrepose from time to time.

I do not confine myself to any particular construction of the battery,and my invention merely consists in the employment of the new lillingmaterials. Therefore,

What I claim, and desire to secure by Letters Patent of, the UnitedStates, is-

As a illing material for galvanic dry bat- IOO tei-ies finely chopped orground vegetable specification in the presence of twosubscribsubstances, and especially chopped straw, ing Witnesses. mixedwith hydrates of carbon, such as starch,

T T T glucose, dextrine, and the like, in combina- JOHB VOL DER POPPEBBURG 5 tion with a solution of hydroxide of chrome, W'itnesses:

substantially as and for the purpose set forth. L. A. EDWARDS,

In testimony whereof I have signedthis HAUPT.

